CORALVILLE, Iowa -- It could be weeks before authorities know what killed an Arizona man who had a chaotic run-in with police earlier this week and died a day later.

Johnson County Attorney Janet Lyness said toxicology and lab analysis for 40-year-old Thomas Martinez, Jr. will likely take several weeks. Until then, Lyness said officials won't know for certain what killed him.

"We have to wait until the autopsy and toxicology come back," she said.

In the meantime, all four officers involved in the incident remain on active duty. Coralville Police Chief Barry Bedford said he is limited in what he can say so as to not interfere with the ongoing investigation, but emphasized the faith he has in his officers has not been shaken by this incident.

"I have full confidence in my officers' performance on a daily basis," Bedford said Thursday. "I have every expectation the results of this investigation will show they continue to follow protocol and accepted standards."

Martinez, of Apache Junction, Ari., died Tuesday night in the Intensive Care Unit of the University of Iowa Hospitals and Clinics, a day after he had an encounter with police in a Coralville business that officials have described as drug-fueled and out of control. The Iowa Division of Criminal Investigation is assisting in the death investigation.

According to Lyness, a Coralville police officer responded to a business in the 2400 block of Second Street – better known as the Coralville Strip – at 3:45 p.m. after employees called 911 and reported Martinez was acting violently and destroying property.

"His behavior was totally out of control," Lyness said. "He was turning over tables."

Two more officers arrived to back up the original officer, Lyness said. Employees in the business hid sharp utensils out of fear Martinez would harm others.

Police said it was evident upon their arrival that Martinez was suffering from some sort of medical issue – he was sweating profusely, his eyes were dilated and officers were having difficulty understanding the man. Lyness said he was also appeared to be having "mini seizures."

"Clearly, when the officers got there, they could tell there was some kind of medical problem," she said.

Authorities later learned from Martinez's family and hospital staff that he might have consumed "multiple" drugs prior to the incident. What he might have been taking is still under investigation, Lyness said.

"I think we'll have to wait for the toxicology reports to know," she said. "We've heard anecdotally, but until we get the toxicology, I don't want to speculate."

Officers requested the Johnson County Ambulance Service respond to the scene due to Martinez's medical condition. A fourth officer responded with the medical responders, Lyness said.

Lyness said the paramedics tried to speak with Martinez, but he became violent, flailed at the officers and paramedics and hit an officer.

At this time, one of the officers deployed a stun gun in an attempt to subdue Martinez. Police said Martinez continued to act violently and attempt to hit the officers. The officer used the stun gun a second time. That calmed Martinez down somewhat, Lyness said.

"After they activated the stun gun a second time, he was able to talk to officers," she said. "He wasn't real coherent, but he was able to talk to them. It wasn't like he was stunned and then lost consciousness."

Paramedics administered medication to Martinez, but as he was being loaded onto a stretcher for transport to the hospital, he stopped breathing. Lyness said the paramedics began CPR and administered another medication and Martinez resumed breathing.

Lyness said she doesn't know what medications were given to Martinez.

Martinez arrived at the hospital around 4:17 p.m. Monday. Lyness said he died Tuesday evening at the hospital.

At this time, the incident is being treated as a death investigation.

"We're just trying, at this point, to gather all of the information so I can't say where the investigation is going," Lyness said.

Bedford said the department has used stun guns for many years. Regarded as a "less lethal" option for police officers, Bedford credited the devices for limiting injuries to both officers and suspects.

"Generally, the people who the Taser has been used on are not injured," he said, noting all officers receive stun gun training in the police academy and most have voluntarily been stunned with the device. "As soon as it's discharged, it's over. There's very little lingering effect. They don't get hurt and the officers don't get hurt."

As with any use of force, an officer who deploys a stun gun will have to articulate why that level of force was warranted, Bedford said. Every use of force incident is reviewed by the department and this incident will be no different, Bedford said.

Despite his confidence in his officers and their actions in this situation, Bedford said he recognizes the public will likely have the department under a microscope while the investigation plays out.

"Any type of in-custody death or any death in anyway associated with police action is always going to be, and probably should be, scrutinized by the public," he said. "I'm not afraid of that. Immediately after this happened, I contacted Janet Lyness and wanted DCI to come in and independently investigate this for transparency. I don't have a problem with people asking questions. I would love to - eventually - answer as many of those questions as possible."